1. Field of the Invention
The present invention relates to a heat sink of a module with a built-in IC, and more particularly to a heat sink of a module with a built-in IC which includes a depressed structure formed at a module case receiving an IC, in particular, a metal-attached IC, so as to form a heat transfer path extending from the metal-attached IC to the module case via conductive materials, thereby allowing heat generated from the metal-attached IC to be efficiently outwardly discharged via the module case.
2. Description of the Related Art
Generally, a cable modem, so called a xe2x80x9ccable modem boxxe2x80x9d, is mounted to a personal computer (PC) while being connected to an Internet connection cable so as to allow the user to have access to the Internet. Such a cable modem can be used in systems requiring access to the Internet, for example, TVs or VCRs, in addition to PCs.
An example of such a cable modem is a cable modem tuner. In order to achieve an improvement in performance and productivity, such a cable modem tuner is manufactured to have a modular structure. In such a modular cable modem tuner, a highly integrated IC is built in a circuit board enclosed in a module case.
FIG. 1 is a perspective view illustrating the outer structure of a conventional cable modern tuner. Referring to FIG. 1, the conventional cable modem tuner, which is denoted by the reference numeral 10, includes a metal case 11 so that it has a modular structure. Pins 13 extend outwardly from a side surface of the metal case 11 while being connected to a circuit board (not shown) mounted in the metal case 11. A plurality of through holes 12 are formed at one major surface of the metal case 11 in order to outwardly discharge heat generated in the metal case 11.
In order to obtain a miniature modular structure, the internal circuit of the cable model tuner module should be implemented using a highly integrated IC. In this case, however, it is also necessary to implement a heat sink because the highly integrated IC generates a large amount of heat. To this end, simple holes are formed at the metal case in the above mentioned conventional cable modem tuner module. However, such holes have an insufficient heat discharging effect. For this reason, the conventional cable modem tuner module has a problem in that a degradation in performance occurs due to thermal noise caused by heat generated from the internal IC.
Therefore, the present invention has been made in view of the above mentioned problems, and an object of the invention is to provide a heat sink of a module with a built-in IC which includes a depressed structure formed at a module case receiving an IC, in particular, a metal-attached IC, so as to form a heat transfer path extending from the metal-attached IC to the module case via conductive materials, thereby allowing heat generated from the metal-attached IC to be efficiently outwardly discharged via the module case.
In accordance with one aspect, the present invention provides a heat sink of a module with a built-in integrated circuit (IC) comprising: a circuit board formed with a plurality of first through holes extending from an upper surface of the circuit board to a lower surface of the circuit board; a metal-attached IC mounted to the lower surface of the circuit board and attached at an upper surface thereof with a metallic member; a first conductive material provided at the upper surface of the circuit board, the first conductive material filling the first through holes so that it is in contact with the metallic member; a module case adapted to receive the circuit board therein while including upper and lower cases made of a metal; and a depressed structure formed at the upper case and adapted to allow the first conductive material on the upper surface of the circuit board to be in contact with the upper case.
Preferably, the depressed structure is integral with the upper case. The depressed structure may have a multi-step structure. The depressed structure may have a plurality of second through holes extending from an upper surface of the depressed structure to a lower surface of the depressed structure at a region where the depressed structure is in contact with the first conductive material. In this case, the heat sink may further comprise a second conductive material provided at the upper surface of the depressed structure, the second conductive material filling the second through holes so that it is in contact with the first conductive material.
Preferably, the contact area between the depressed structure and the first conductive material is substantially equal to the contact area between the metal-attached IC and the circuit board. The first and second conductive materials may be provided using a soldering process.
In accordance with another aspect, the present invention provides a heat sink of a module with a built-in integrated circuit (IC) comprising: a circuit board formed with a plurality of first through holes extending from an upper surface of the circuit board to a lower surface of the circuit board; a metal-attached IC mounted to the lower surface of the circuit board and attached at an upper surface thereof with a metallic member; a first conductive material provided at the upper surface of the circuit board, the first conductive material filling the first through holes so that it is in contact with the metallic member; a module case adapted to receive the circuit board therein while including upper and lower cases made of a metal; and a depressed structure formed at the upper case and adapted to allow the first conductive material on the upper surface of the circuit board to be in contact with the upper case, the depressed structure being formed by partially cutting out a portion of the upper case, and downwardly bending the cut-out portion of the upper case.
In this case, the depressed structure may have a plurality of second through holes extending from an upper surface of the depressed structure to a lower surface of the depressed structure at a region where the depressed structure is in contact with the first conductive material. The heat sink may further comprise a second conductive material provided at the upper surface of the depressed structure, the second conductive material filling the second through holes so that it is in contact with the first conductive material.
The contact area between the depressed structure and the first conductive material is substantially equal to the contact area between the metal-attached IC and the circuit board. The first and second conductive materials may be provided using a soldering process.